I add this little 'story' here as a warning, that may be helpful for performance troubleshooting.

Some time ago I bought used MINI ITX motherboard with Intel T8100 CPU and 965GM chipset, it came along with used 2 x 512MB RAM 667MHz DDR2. I already had 2 x 2GB RAM 800Mhz DDR2 from my older box, so the first thing I did after assembling all the parts was upgrade the amount of RAM.

The system worked well, 50+ days of uptime until power loss from time to time, it has ZFS mirror on 2 x 2TB drives. But I 'found' some strange performance problems.

So I started to look for the cause of the problem.

First I thought its slow because I have 80% filled ZFS, but after upgrade to 8.2-STABLE and various performance improvements it should not be a problem.

Then I thought that CPU may be overheating ... but it wasnt.

My 2TB disks are LOW POWER Seagate's so I thought that maybe their random access time is so low that its because of that, nope.

I also thought that it may be because of maybe broken 8GB CompactFlash card that is used for hte base system, nope.

At that point I did not had any clues what to check more.

But I thought, maybe I will also check memory ...

I found some nice simple memory allocation benchmark called ebizzy (nor in ports) and run # ebizzy -s 4096 to check the speed, compared with memory allocation speed on somparable laptop ... and VIOLA! Thats the problem.

I have just 'degraded' memory from 4GB 800MHz to 1GB 667Mhz and now allocations in ebizzy raised from 11462 records/s into whooping 2347823 recors/s

Also ffmpeg performance improved from 0.2 FPS into ... 40 FPS

Its because 965GM chipset maximum frequency is 667 MHz.

You have been warned ]:->

__________________religions, worst damnation of mankind"If 386BSD had been available when I started on Linux, Linux would probably never had happened." Linus TorvaldsLinux is not UNIX! Face it! It is not an insult. It is fact: GNU is a recursive acronym for “GNU's Not UNIX”.vermaden's:linksresourcesdeviantartspreadbsd

The story sounds little bit strange since DDR 2 800 is suppose to be backward compatible with DDR 2 667. In another words. DDR 2 800 should have been detected as 667 if that is what the maximum memory speed of your mother board should have been.

That's what I also thought, I checked BIOS options, but this motherboard does not offer any manual settings for the memory.

__________________religions, worst damnation of mankind"If 386BSD had been available when I started on Linux, Linux would probably never had happened." Linus TorvaldsLinux is not UNIX! Face it! It is not an insult. It is fact: GNU is a recursive acronym for “GNU's Not UNIX”.vermaden's:linksresourcesdeviantartspreadbsd

__________________religions, worst damnation of mankind"If 386BSD had been available when I started on Linux, Linux would probably never had happened." Linus TorvaldsLinux is not UNIX! Face it! It is not an insult. It is fact: GNU is a recursive acronym for “GNU's Not UNIX”.vermaden's:linksresourcesdeviantartspreadbsd

__________________religions, worst damnation of mankind"If 386BSD had been available when I started on Linux, Linux would probably never had happened." Linus TorvaldsLinux is not UNIX! Face it! It is not an insult. It is fact: GNU is a recursive acronym for “GNU's Not UNIX”.vermaden's:linksresourcesdeviantartspreadbsd

Yeah, that is odd. I added two 800 MHz sticks to a computer with two 533 MHz sticks already in it and it worked fine. The BIOS recognized it as 800, so I think they just didn't put the max MHz RAM in to begin with.